Tension-distributing means for machine-shear hand pieces



Feb. 15, 1927 I 1,617,436

r c. H. DAVIS TENSION DISTRIBUTING MEANS FOR MACHINE SHEAR HANDPIECE I S Filed Oct 6. 1924 Patented Feb. 19 27..

CHARLES HENRY DAVIS, or rivvnnnrm, NEW 'sourrr vrALEsfAusfi itALrA.

TENSION-DISTRIBUTING MEANS FOR iriion nn-snnnninnrin Pincus. i

Application filed October 6, 1924, Serial No. 741,874, and. in Australia December 4, 1923'.

When the fork of the vibrating lever of a sheep-shearing machine bears directly on the'back of the cutter, imperfectdistribu-- tion of the pressure (called tension in the art) results, and the shear then operates unsatisfactorily. The cutter consists of an open bottom sheet metal stamping which Is detachably held by the lever fork and works across the comb face; it is taken out of the machine from time to time and ground on the bottom'face to sharpen its cutting edges. The grinding is rarely exact and the parallelism of the cutter face with the cutter back is thus frequently rendered so irregular that a tension justifying device must be interposed between the cutter and the fork of the lever; Various devices have been used for this purpose, and though certain of these known devices operate with greater or less utility, allof them which are within my knowledge possess defects which it is (iBSlI? able to eliminate.

In my invention the forward end of the I cutter driving lever is formed as a flat palm with an approximately straight front edge; it is not forked to form claws as is usual in shearing machine construction. The forward part of the lever palm extends slightly forward of the back line of the'cutter.

spring tension justifying plate is secured below this palm. This plate extends over the top of the cutter and'it bears onthe tops of the cutter teeth along its frontal edge, which is finished to the radius of thecutter movement, and it carries the driving dowels and is so shaped that it effects equalized distribution of the tension as between the three teeth of the cutter, so that the necessity for providing a centre spring finger or any equivalent device for adjusting the pressure on the centre finger in relation to the outer fingers is obviated. The ad justment is perfected in special cases by very slightly grinding down the top face of the centre tooth of the cutter where'the tension justifying plate bears upon it. The spring plate islocated in a countersunk seating in the bottom side of the lever and it is fixed to V the lever by a rivet or screw at its extreme rear end. It is thus rigidly held by the lever but is free to flex to accommodate. it to the cutter. I

The invention will now be described with reference to the accompanying drawings, 'in which-. a

Fig. 1 is a top plan of the fore end of the driving lever finished to a palm, and fitted,

with-1a tension justifying plate which is shown bearing on a three tooth'cutter of con-' ventional type Fig. 2 is a sion justifying plate, indicating itstransverse curvature by reason of Y which it is caused to contact firstly on the backs of the. outer teeth of the cutter, and subsequently on the back of the middle toothiof the cutter.

front end elevation of the ten Pressure is thereforeapplied only on the-2 middle tooth of the cutter when the tension screw is screwed down sufliiciently "to straighten the plate, the curvature of the plate having regard'toits shape, being such that additional pressure. applied afteran. overall equalized bearing is attained results in the application of more pressure on the centre tooth of the cutter than :on the outer teeth of the cutter; Fig. 3 is a longitudinal-section "on the line 3-3 Fig.1

Fig. 4f is a front end ter; and i Fig.5 is a top plan of the cutter.

The vibrating. drive lever 10 may be of any one of the conventional types, but inall cases it is:terminated at its forward end in a fiatsplayed member or palm 11, the forward end 12 of which extends forwardly elevation of the out slightly over the back edge .13 of the cutter if 14. The tension justifying plate 15 is a'flat plate of spring steel extending across the cutter back 14 and having arearwardly disposed triangular stub extension 16, the apex at the back end of which is riveted or screwed up at 17 to the wrist-portion ofthe palm 11. The under side of the palm 11 is countersunk to form a neat seating for the it is also curved transversely sov that when free it is slightly concave on the under side, and it should =be' hollow ground -or relieved behind its forward bearingzed'geas shown at '19 so that it contacts With the backs of the cutter teethonly on a line as nearly as possible forward on the cutter teeth backs.

' This'is clearly seen in Fig. 3. The driving dowels are fixed in'the justifying plate 1 5, and asvusu'al-they take into the drive holes 21 in the cutter back. Facility of adjust men't is:obtained1inzparticularfcases by more Q or less grinding down ;the :top face :of ;the

middle tooth of the cutter as shown at .22.

Thisgrinding down is effected by the shearer,-andiis resorted toionly "for the :purpose of modifying :theadjustment as between the i sureion the middle tooth as contrasted Without'erlteeth land the .winiddle tooth which is a otherwise obtained by means ofrthe platel5.

Whentension (downward pressure?) is :ap-

plied .tozthe drive lever 1O, it is transmitted v throughithe justifying :plate 15 to the cutter 14. 'iGonsequen't on the lateral curving of the-justifying :plate 15, this plate contacts firstwvith .thebacks of .the outer teeth of the cutter; .asitensiOn is increased *itrflexes ztrans 1 verselyiso that :thezmiddle lPOl'tlOILQf it then contacts with the :back'ot rthe :niiddle tooth olfthe .cutten -Further increase in the ten 'sion Pafterthe point loff iequali-zation is passed results in disproportionate increase dfzpresthgelpressureeapplied:to the two outer teeth of the cutter. By using the ordinary tension adjustment screw the shearer :is :enabled :to

ease up or intensity .the'tension on the 'middle point of the cutter, Whilst maintaining tension on the outersteeth of it. In View of the flat ing like fornnof the plate 15, :it is capable of flexing .more or -lessfreely.upwardly"when,considerahleqoressure is applied to the cutter lever 10, but "its freedom to flex upwardly ilS greater at "the gside s than at the .centrelsoithat wheniazheavy tension is lapplied Ito iOlQtfLlIl ;a desirable :cut- 7 Y tinglcontact atithemid'dle:tooth,thetension 1 a is not augmented to the same extent on the outer teeth as on the centre tooth, this by reason of its elasticity at its outer portion.

The fiat shapeof the justi-f ying plate and its close down location rover the cutter back minimizes the risk of its catching in the fleece during the shearing of sheep as it Works freely in "the opening in the fleece and does front edge and flexible tension-justifying lVhat I .olaimas myrinvention-and desire plate With its front edge finished to the radius of the cutter amovement and bearing down-ward on the backs of the cut er, teeth near their :forward ends, said plate having a :rearward central angularstub :located-in a countersunk seat and fixed near its rear end to the unders'lde of said :lever.

2; Ash'eep shearinganachinextensionadjust-v ng device intermediate the cutter lever :and the cutter, constituted at a .flexible tflat plate carried by the cutter lever :and having its front edge :finished :to the radius of the cutter movement and adapted ito closely overlie the cutter :back and to bear at its- -frorit edge only at forward positions on the backs of,

the cutter teeth; e l

3. A sheep shearing machine tension 1adjusting device according to claim 25 having the flexible flat plate scalloped-or fluted longitudinally on the top face bearing edge.

4:. A sheep "shearing machine :tGIISl'OIL-fidjusting device according to:claimQ :norma'lly curvedato:bear'initially on the outer teethlof the cutter and by \virtuelof lits flexibility and plain :shape adapted to hex :more treely rat its endszthan, at its mid part Whentension is applied to the :lever. V V

:In testimony whereof I have name to this specification.

CHARLES HENRY'DAVIS.

st ned my of it adjacent its 

